package day07;

import java.util.Random;

public class VerificationCode {
    public static void main(String[] args) {
        String code = generateVeriCode( 6);
        System.out.println("验证码："+code);
    }
    public static String generateVeriCode(int len){
        String code = "";
        char[] chs = {'a','b','c','d','e','f','g','h','i','j','k',
                      'l','m','n','o','p','q','r','s','t','u','v',
                      'w','x','y','z','A','B','C','D','E','F','G',
                      'H','I','J','K','L','M','N','O','P','Q','R',
                      'S','T','U','V','W','X','Y','Z','1','2','3',
                      '4','5','6','7','8','9'};
        Random rand = new Random();
        for (int i = 1;i<=len;i++){
            int index = rand.nextInt(chs.length);
            code += chs[index];
        }
        /*
        i = 1    index = 0      code = "0"
        i = 2    index =       code = "0"
        i = 1    index = 0      code = "0"
        i = 1    index = 0      code = "0"
        i = 1    index = 0      code = "0"

         */

        return  code;
    }
}
